I got a call from a prospective client today and whilst speaking about different things on FM he asked me something which really surprised me.
He has an FM solution for customers, invoicing, etc. and the solution is on FM 11. When he makes a Find request in the Customer Balance to get all the customers that owe him more than an amount X, the correct results show up but also a whole lot of customers with Balances of zero (0). Also he told me that this issue cropped up around a year ago.
I know its a bit vague and I still haven't got a look at the database just yet but I was wondering if anyone has ever come across something like this to point me in the correct direction.
If the issue just suddenly appeared without any changes to code, it likely is index damage. Go into Manage > Database and turn off any indexing, but leave the selection to have FileMaker build indexes automatically selected. Save the change. The next time someone does a search on the field, it will automatically rebuild the index and often will clear up this sort of issue.